This is the H2X Shaft Pin with SKU number X400130 and is one element that goes with the Blade Prop Kit. The H2X Shaft pin is a prop shaft pin and is a component of the wave propulsion.
Has the ball in your air control become stuck, or has it started to “whistle?” It is most likely time to replace it. Master Spa Parts has the perfect replacement part for you. The 1-Inch, MG Air Control w/ Blower Assist Tee is compatible with spas and hot tubs that accept a one-inch air control.